Long Beach dredging project pushes to meet deadline

LONG BEACH - The push is on to move 40,000 cubic yards of sediment from the floor of Alamitos Bay to the Port of Long Beach by the end of the month.

To make the deadline, work crews are dredging the bay's Basin 1 around the clock, seven days a week, 24 hours a day.

A total of 60,000 cubic yards of sediment will be moved - but the port only wants the two-thirds of the material that is contaminated by mercury, according to Mark Sandoval, the city's Marine Bureau manager.

The material will be used for the port's Middle Harbor terminal redevelopment project, a $1.2 billion, 330-acre expansion slated for completion in 2019.

Because the sediment will be above ground and will be trapped in the middle of concrete, contamination isn't a factor, port officials said.

The remaining 20,000 cubic yards of clean sediment will be moved out to the ocean.

The Middle Harbor will ultimately require about 5.4 million cubic yards of fill material, according to Art Wong, the port's assistant director of communications.

"The project itself will create about 2.2 million cubic yards of material," he said. "So we need another 3.2 million cubic yards from other sources."

The port has identified 1 million cubic yards from Newport Beach, Los Angeles County and elsewhere in Long Beach, Wong added.

Over the years, sediment - moving in undercurrents - gets deposited in various marine spots. Contaminated sediment, generally from industrial sources, pollutes the water, which in turn creates a hazard for fish and humans.

Sandoval said the source of the contamination of the marine sediment isn't known, adding that it's strangely located only in Basin 1.

The dredging will include using a "DB-24," a 60-by-120-foot, 120-ton derrick barge with a clamshell bucket.

In an advisory to boaters and businesses in the marina, 3rd District Councilman Gary DeLong said that an estimated 3,000 cubic yards of excavated material, known as spoils, will be generated every 24 hours.

A boom with a silt fence will protect the work area, and spoils will be deposited into two alternating flat-bottom boats, each with a 2,000 cubic-yard capacity.

The boats will leave Alamitos Bay's main channel every four to six hours to the Middle Harbor project site, or to an offshore disposal site, according to the councilman's office.

The dredging began June 14 and should be completed July 14, Sandoval said.

Following that, the work crew will begin driving piles into the cleared terrain for the construction of new boat slips.